Casting machine



Jan. 8, 1929. 1,698,197

J. A. LENTZ CASTING MACHINE Filed March 27. 1922' s Sheets-Sheet 1 gg/WE IN VIEINTORZI I John. fl Lenlz,

J. A. LENTZ CASTING MACHINE Jan. 8, 1929.

Filed March 27. 1922 3 Sheets-Sheet 2 mvswrca John/1. Le n12. 5 Afi' Jan. 8, 1929; 1,698,197

J. A. LENTZ CASTING MACHINE Filed March 27. 1922 a Sheets-Sheet 5 a g :s

fag I \\\1 .INVENTOR.

I John/ L Lentz,

Patented Jan. 8, 1929.

UNITED STATES JOHN A LENTZ, .OF PHOENIX, ARIZONA.

casrnve monmn.

Application filed. March 27, 1922. Serial No 547,183.

-My invention relates to casting machines adapted for making castings in general, and

for making dental castings in particular, of

metal, porcelain, or other material suitable for the respective purpose, such asinlays,

v backings, dummies, cusps, crowns, bridges,

plates, saddles, clasps, bars, regulating appliances and the like; and particularly pertains to that class of casting machines in which the metal or material to be cast is melted by a blow-pipe or other suitable cavity by a spruewa-y, and is forced through means, in a crucible, is poured into acrucible c'avity formed in the top of an investment held in a ring or flask containing a mold chamber communicating with the crucible the sprueway into the mold chamber by air. or other suitable gas under pressure; or, is melted directly in the crucible cavity, and in like manner forced into the mold chamber.

The objects of the invention are asv follows:

First: In making castings, to give the operator a choice, either to melt thematerial to be cast directly in the crucible cavity of the investment, when heating the investment is an advantage or, to melt the material in a crucible removed from the investment and automatically pour it into the crucible cavity of the investment, when it is desired to not subject the investment to unnecessary heat.

Second: To give the operator a. choice, according to requirement of each case, either to manually manipulate the blow-pipe flame on the crucible, or the crucible cavity of the investment; or, to have the blow-pipe automatically held and moved into and out of position.

-' Third: To provide a means for regulating the flame producing gases according to use, and to obviate to a great extent repeated regulation to obtain proper mixture of gases at each casting operation.

" Fourth: To provide automatic means of shutting off the gases to the extent and at the time desired.

greater pressure, and so maintained as long as desired.

Sixth: To provide a means whereby the port area of the openings through the cap that seals the crucible cavity of the investment, may be varied if deemed desirable.

Seventh: To provide a means for preheating the gas delivered to the sealed crucible cavlty.

Eighth: To provide a means for co-ordimating the above automatic movements, so that the movement or operation of one main lever or mechanical means will efi'ect the operation of all.

Ninth: To provide a mechanism whereby on operation of a lever, a crucible, containing the molten metal or material, may be advanced or retracted relative to a flask and tilted to discharge its contents into the crucible cavity of the flask when in its advanced position, and whereby continued movement of the lever will effect sealing of the crucible cavity after retraction ofthe crucible; and whereby. further continued movement of the lever will automatically admit air or other suitable gas under pressure to the sealed crucible cavity to, force the molten metal or material into a mold chamber .in the flask, and, if desired automatically increase such pressure, as desired; and whereby return of the lever to its initial position will auto- 'matically, restore the crucible to its initial position.

With-the above stated objects in view, and also such other objects as may subsequently appear, the invention resides in the parts and in the construction, combination, and arrangement of partshereinafter described and illustrated in the accompanying drawings in which: a various cond1t1ons,.purposes and modes of "Fig. 1 is a perspective viewof the machine with parts broken away, with the mechanism set in readiness for operation;

Figs. 2, 3 and 4 are sectional views of various flasks employed in the machine;

Fig. 5 is a view in section and elevation as seen on the line 5-5 of Fig. 1, showing the parts as arranged after operation of the lever to seal the flask and preceding the delivery of air to the flask;

Fig. 6 is a detail section in elevation as seen on the line 6-6 of Fig. 5;

Fig. 7 is a detail of a cut-0E valve;

Fig. 8 is a detail section on line 13-13 of Figurerfi;

Fig. 9 is a partialelevational and sectional view taken on the line of 9-9 of Fig. 1;

Fig. 10 is a partial plan and sectional view taken on the line 10-10 of Fig. 9;

Fig. 11 is a sectional detail taken on the line 11-11 of Fig. 9;

Fig. 12 is a detail section on the line 12-12 of Fig. 9;

Fig. 13 is a sectional perspective on line 14-14 of Fig. 9.

Referring to the drawings more specificall the several units constituting the assem ly of my machine comprise a base unit 15, a gas pressure unit 16, a crucible unit 17, a capping unit 18, a gas valve and blow pipe unit 19, and a flask unit 20.

The base emit. The base unit comprises a plate formed with a vent opening 2l, encircled by a series of annular concentric grooves 22 formed in the upper surface 23 of a base plate. The grooves 22 are connected by radial grooves 24. The grooves and vent opening constitute air passages to permitair to pass from the flask unit, as will later be described. Formedon the base plate, and surrounding the annular grooves 22, is a series of annular beads" or walls 25 having aligned openin s 26, therein forming passageways through t e walls 25 leading to a depression 27 in the surface 23. The walls 25 form troughs for the collection of particles of escaped metal, and also constitute flanges for the centerin the flask unit. A flan e28 extends aroun the outer edge of the ase plate, forming a basin throughout the top thereof.

The gas pressure unit.

The gas pressure unit 16, particularly shown in Figs. 1, 5, 6 and 7, includes an ordinary gas pressure regulator 29 adapted for converting a higher pressure into a lower definite pressure and capable of adjustment to deliver dilferent definite pressures with the same resistance offered to gas exit, within the limits of the instrument, by turning an adjustment wheel 40 projecting from the top' ofthe regulator and provided with two shallow drill holes 40" for application of a suitable adjustment wrench. There is nothing novel about the regulator, and any regue T-coupling has a passage way 1) 'connecting with the passage a of the gas regulator, in which is disposed an electric heating element 32 adapted to heat the gas flowing through the passage b. Supported on brackets 33, is a cylinder 34 having a nipple 35, adjacent one end fitted with a screw 36 threaded in the nipple, and adapted to vary the size of a vent formed in the nipple.

Mounted in the cylinder is a piston 37 on a rod 38 connected with the adjustment wheel 40, as will presently be described; there returned to the cylinder on the opposite side of the piston wit out changing the nature of the invention. A handle 40, adjustably fixed at the clamping screw 40 to the wheel 40, is connected by a link 42 to the rod 38, so that as the latter is reciprocated, the wheel 40 will be turned. Pivoted at a, on the cylinder 34, is a trigger device 43 comprising a catch 44 adapted to be engaged with a slot 45 inthe rod 38 tohold the latter inv an advanced. position in opposition to the spring 39; a spring d, acting on the trigger 44 to hold the latter inits rod engaging position. A trip lever 46, pivoted at e, has a finger on one end engaging the catch 44, and.

has its opposite end upturned and positioned to be operated, as will presently be described,

to trip the catch 44. A lug 40, adapted to slide on rod 38, andto be clamped tightly into any position along rod 38 by the clamping screw 40, is designed to stop the forward movement of the piston 37 actuated by spring 39 during any part of the stroke, thereby stopping the rotation ofwheel 40 and maintaining the pressure thus far produced. A twoway valve 47, mounted on an operating lever 48 pivoted at f, isprovided with a disc 49 fixed to the valve stem 47",

and formed on the edge of the disc as a tooth 50 and handle 51; projecting from the and by means of a by-pass, the vented liquid disc is a pin 52,, adapted to engage the trip lever 46 on turning of the disc 49 when the lever 48 is disposed in its horizontal locked position. A stop pin 53 is fastened in the casing of the va ve 47 to limit travel of the disc 49, being arranged in the path of travel of the tooth 50. Pivoted at g, on'th'e lever 48, is atrip arm 54 adapted to engage the tooth 50, and extending between the handle.

51 and down turned arm 55 on the trip arm 54 is a coil spring56, tensioned to maintain the trip arm in engagement with the disc, and to exert a pull on the handle 51 to rock the valve on disengaging the trip arm from the disc. A locking lever 57 is pivotally mounted at h on the base plate and is held I forwardly by a plate spring 58, and formed on the locking lever is a shoulder 59, and formedabove the shoulder is a curved face 60. A dependent bracket 61 is fixed to the operating lever 48 and has an elongated slot 62 disposed to be engaged by the shoulder 59; the bracket being adapted to engage the curved face 60 and pushthe lever "-57 backward on downward movement of the operating lever. The arm 55 of the trip arm ranged, the valve being formed with a part adapted to be moved in and out of register with the passage 64. The port 65 is closed to the passage 64 when the disc 49 is engaged by the trip arm and is designedto be opened to the passage 64 on rotation of the valve under action of the spring 56.

One end\ of the passage 64 isconnected by a flexible tube 56 to the passage 5 in the T- coupling 30, and-the other end of the passage 64 connects with 'a flexible tube 67 leading to a tube 68 on a cap 69 of the capping unit 18; the tube, 68 opening through a port 70 to the interior of the cap.

A pressure gage A is connected to the T- coupling 30 to indicate the air pressure in passage 5.

The flask unit.

The flask unit comprises an open ended tubular casing 73 containing an investment 74 formed of porous material provided with.

a mole cavity 75 and a sprueway 76; the upper surface of the investment being concave to form a crucible cavity to receive molten metal as is common in devices of this character. The flask may be formed in any desired manner according to the work tobe performed, and is designed to be seated on the base plate and centered over the vent 21;

the flask either being seated directly on the base plate as shown in Figs. 2, 4 and 5 or seated on a fillet block as shown in Fig. 3, in event the flask is short in length.

The capping wait.

the yoke, whereby the lever 48 may have downward movement relative to the cap, after the latter has been seated on the flask.

A spring 82 is interposed between the lever and the cap as a 'means for normally maintaining the trunnions in the outer end of the slots and for yieldably opposing the movement of the lever 48 after the cap is seated. The cap is formed with a distributing chamber 83 with which the port 70 communicates; this chamber having a perforated wall 84 opening to the underside of the cap. A small circular disc 84 With openings registering with those on the under surface of perforated wall '84, ispivoted centrally against the under surface of the perforated wall 84, so that by rotating the disc 84, the openings in wall and disc may be brought in and out of register, and thereby efl ect the volume of air or gas delivered to the crucible *cavity.

- The crucible unit.

cam cylinder 91 mounted on a rock shaft 92,

on which the operating lever 48, pivoted at f, is rigidly mounted. The cam cylinder 91 is formed with a cam recess 93 of substantially triangular form, and mounted within,

the recess is a spring tensioned guide frog 94 of substantially triangular form, one corner of which normally abuts against the side wall of the cam recess, and the sides of which are spaced from the walls of the recess, forming a channel which is interrupted at one point by the frog. The end of the stem 87 is fitted with a knob 95 which projects into the recess 93 in position to be engaged by the walls of the latter in such manner that, as the cylinder is turned on initial downward movement of the lever 48, the knob 95 will be caused to traverse an inclined portion of the cam channel by action of the uide frog so. as to swing the crucible inward y toward the flask during the par 'al downward movement of the lever; the kn b moving into a reverse inclined portion of t e cam channel on continued downward movement of the operating lever to cause the crucible to be retracted relative to the flask; and the knob traversing a circumferential portion of the cam channel throughout the remainder of the down stroke of the lever to maintain the crucible in its retracted position. The knob traverses a circumferential portion of the channel on upward a downturned finger 97 on the shank 86 as the latter moves forward in such manner as to rock the latter to tilt the crucible downwardly. A second prong 98 engages the finger 97 on, rearward movement of the shank to restore the crucible to a horizontal position and to maintain it in such position until acted on by the prong 96. The crucible and its mountings may be removed when it is desirable to melt the material to be cast directly in the crucible cavity of the flask.

The gas valve and the blow pipe unit.

i Mounted on the base plate is a "tubular standard 99 constituting a casing for a rotary. valve 100 having a pair of horizontal angular ports 101 and 102 adapted to be moved in and out of register with intake ports 103 and 104, and outlet ports 105 and 106. The horizontal angular port 101 is continued for a short distance on the external surface of the rotary valve 100 as a groove 0 gradually diminishing cross area from the port openings in a direction opposite to that in which rotary valve 100 is turned to shut off the gases. The inlet port 103 connects with a source of a suitable combustible gas supply through a regulating needle valve 107 and a cut-off valve 108.

The intake port 104 connects with a source of a suitable oxidizing gas as nitrous oxide,

oxygen or air, through a regulating needle valve 109. In accordance with the manner in which it is desired to operate this blow pipe, the respective gas supplies to 103 and 104 may be reversed. The outlet ports 105 and 106 connect with a common passage 110 connecting with a flexible conduit 111 leading to a blow pipe 112 supported in an adjustable bearing 113 on a standard 114 projecting axially from the valve 100, so as to turn with the latter and effect an oscillating for effecting movement of the valve'100 to automatically close the ports and cut off the supply of gases to the blow pipe, a pin 115 is provided on the valve 100, adapted to be positioned .to project in the pathof travel of a pin mounted on the end face of the cam cylinder is turned by depressing the operating lever the pin 115 and cause the valve 100 to turn a partial revolution during the nitial movement of the cam cylinder, shutting off the supply to 102 and reducing the supplv to" 101. As the simultaneous shutting off of both gas supplies is likely to cause an'explosion of gases, where oxygen is one of the gases employed, it is advisable to allow at As a means '48, the pin 116 will engageleast a partial flow of gas through 101 fora limited time. Where the combustible gas is connected with 103, this results in a pilot I gradually brought back to operating pos1- tion, with pin 115 in contact with pin 116, the combustible gas supply is again restored already regulated needlevalve 107, and likewise the oxidizing gas supply is again restored to the proper flow, as maintained by the already regulated needle valve 109. Where the supply of gases is reversed, the

operation of rotary valve 100, by the move- 'ment of main lever 48, is to shut oif the combustible gas and the flame and to reduce .the flow of the oxidizing gas, which is then turned off by cut-oif 108. If desired the efl'ect of turning off the cut-ofl' 108 can be automatically accomplished by two additional pins similar to 115 and 116 properly positioned on valve 100and on the end face of cam cylinder 91., respectively, and adapted to impart an additional revolving movement Operation.

In the operation of the invention, several preliminary manual adjustments arev employed before starting the mechanism in operation, to-wit: (a) The operating lever 48 is moved to its uppermost position as shown in Fig. 1, thus retracting the cam cylinder to positionthe crucible in a position to one side of the flask.

(b) The gas pressure regulator 29 is turned on, valve 47 is disposed in its closed position, with the trip arm engaging the disc 49 to hold the valve closed.

.(0) Arm 40 being released from its grip on wheel 40 by unscrewing screw 40 by means of a wrench inserted into drill holes 40*, wheel 40? is turned clockwise, as required, until pressure gauge A shows the d e-v sired initial pressure to be delivered. Maintaining wheel 40 in this position, arm 40'is placed into operating position with trigger 44 engaged in slot 45 on rod 38, with spring 39 under tension. Screw 40 is 'now'tightto the proper flow, as maintained by the f to valve 100 near the completion of the ened, clamping arm 40 firmly to wheel 40.

With an investment filled flask for testing purposes in position, lever 48 is brought down and flask sealed, automatically opening valve 47, tripping the trigger 44 and setting rod 38 in motion, and thereby revolving wheel 40 and increasing the pres- 50' time move the blow pipe nozzle clear out of i is held in this position and lug 40 moved against the cylinder 34 and clamped in position by turning the screw 40, thus fixing the maximum pressure delivered through the regulator. By makingseveral testings, the screw 36 is adjusted to regulate the vent so as to make the desired time elapse between the delivery of the initial pressure to the time maximum pressure is'reached. As there is little occasion for frequent changes in adjustmentof pressure and time before the maximum is reached, when this adjustment is once made, no further adjustment is necessary except for special purposes. These adjustments, therefore, aving been made, arm 40 'is placed in operatingposition with trigger 44 engaged in slot 45 in rod 38. l

(d) A desired flask filled with investment, its upper surface formed into a crucible cavity connecting by a sprueway' to the mold chamber within the investment, is centered on the base plate and positioned to receive the contents of the crucible and to be sealed bythe cap 69 on downward movement of the lever 48. ('0) The current to 32 is turned on. (f) The gas control valve 100 is positioned manually to open communication between the inlet and outlet ports and disposethe blow pipe nozzle over, the crucible by opening cut-ofl valve 108 and turning on the supply of combustible and oxidizing gases and regulating them by needle valves 107 and 109, an infammable gaseous mixture is delivered to the blow pipe. The metal or material tobemeltedis placed in the cruelble and the gas discharged from the blow pipe being ignited the blow pipe is positioned manuallyor mechanically to effect melting of the metal.

(g)'When the material becomes melted the operator moves the lever 48 downward which turns the cam cylinder 91 and operates through the latter to immediately turn the gas control valve 100, and at the same the crucible. During this movement of the cam cylinder, the crucible is carried forward and caused to deposit its contentsinto" the flask. Continued downward movement of the lever causes the crucible to be retracted clear of the flask'in suificient time to permit the cap 69 on the lever to move into position on the flask as the, lever nears the heating element engagementwith the disc on the valve 47, so that the latter will be turned under the action of spring 56 to permit air or other gas used to flow tO'tlle flask. Turning of the disc rocks the lever 46 and lifts the trigger 44 out of engagement with the slot 45 in red 38 and allows spring 39 to slowly turn the wheel 40 until lug 40 stops the movement of rod 38 in the position for delivery of desired maximum pressure.-

The air, entering the flask, operates to force the molten metal through the sprue-' of moderate initial pressure followed by the gradual delivery of increased pressure, has

the effect of absolutely avoiding back pressure, of enabling the first layer of material to be placed against the walls of the mold at a light pressure without injury to delicate and frail portions and without distortion,

mold wall is somewhat congealed, to permit a greater pressure to be delivered without injury than could be safely used where one pressure is applied throughout.

- The locl'zing lever 57 is then -manually retracted 'in opposition to spring 58, whereupon the operating lever 48 may be which operation has no'eifect other than to restore the knob'95 to its position in' the lower part of the cam slot and restore the crucible to its initial operating position. No action will be had on the valve 100, as the pin 116 on the cam" cylinder will move away from pin 115 on its retracted move-' ment.

- I realize that there is nothing novel in" thefollowing combination, namely: a flask containing a m ld chamber connected by a sprueway to a crucible cavity; a-cap adapted for sealing said flask; a means for'sealing said flask with said cap; a means for providing gas. under pressure in the sealed crucible cavity to force molten material from the crucible cavity into the mold chamher; a blow pipe for melting the material to be cast; a means'for supporting the blow pipe in position; a means for regulating the mixture of gases to the blow pipe; a means for shutting off the gases to the blow pipe; anda means for turning the blow pipe out of interference; soI do not claim thiscombination or any one that can be made by rearrangment 'of the various elements in this combination as novel, but I do claim as novel the following:

.and when the film of material next to the manually returned to its uppermost position, I

1. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway witha crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas under ressure in said sealed crucible cavity to orce molten material from said crucible cavity into said mold chamber; a crucible in which the materialto be cast is melted said crucible being separate and distinct irom said crucible cavity and adapted to empty its molten contents into said crucible cavity; and means for automatically causing said crucible to empty its molten contents into said crucible cavity. 2. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask;, a cap adapted toseal said crucible cavity, means for sealing said crucible cavity with said cap; means for initially providing gas under relatively low ressure in said sealed crucible cavity to orce molten material from said crucible from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being separate and distinct from said crucible cavity andadapted to empty its molten contents into said crucible cavity prior to the sealing thereof, means for causing said crua flaskcont'aining amold chamber connect-' cible to empty its molten contents into said crucible cavity; and means for automatically increasing the initial gas pressure provided in said crucible cavity.

4. In a casting machine, the combination of ed by a sprueway with a crucible cavity in said flask; a cap adapted tovseal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavit into said mold chamber; a crucible in whic the'material to be cast is to be melted,

said crucible being separate and distinct from. said crucible cavity and adapted to empty its molten contents into said crucible cavity prior to the sealing thereof; means for causing said crucible to empty its molten contents into said crucible cavity; and means for automatically increasin the gas pressure provided in said seal cruci 1e cavity, from a predetermined initial pressure to a predetermined final pressure.

5. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means forproviding gas under pressure in said sealed crucible cavit to force molten material from said crucib e cavity into said mold chamber; a crucible in which'the material to be cast is melted, said crucible being separate and distinct from said crucible cavity, and adapted to empty its molten contents into said crucible cavity prior to the sealing thereof; means for causing said crucible to empty its molten contents into said crucible cavit and means for automatically increasing t e gas pressure provided in said sealed crucible cavity from a predetermined initial pres sure to a predetermined final pressure, within a predetermined period of time.

6. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being. separate and distinct from said crucible cavity and adapted to empty its molten contents into said crucible cavity prior to the sealing thereof; means for causin empty its molten contents into said crucible cavit and means for preheating said gas prov ded in said sealed crucible cavity.

7. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in saidflask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas'under pressure in said sealed crusaid crucible to cible cavity to force molten material from said crucible cavity into said mold chamber;

means for automatically increasin the ini-' tial gas pressure provided in sai crucible cavity; and means whereby the gas provided in said crucible cavity is pre-heated.

8. In a casting machine, the combinationcavity, from a predetermined initial pressure to a predetermined final pressure; and means .whereby the gas provided in said crucible cavity is pre-heated.

9. In a casting machine, the combination of a flask; contaming'a mold chamber con- ,nected b a spruewaywith a crucible cavity in said ask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas under pressure in said sealed crucible cavit to force molten material from said crucible cavity into said mold chamber;- means for automatically increasing the as pressure provided in said sealed crucible cavity, from a predetermined initial pressure to a predetermined final pressure, with: in a predetermined period of; time; and

cans whereby the gasprovided in said crucible cavity is pre-heated.

10. In a casting machine, the-combination of aflask containinga mold chamber con, nected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with'said cap; means for providin gas under pressure in said sealed crucib e cavity, to force molten material from said crucible cavity into said mold chamber; a crucible in which the material t9 be cast is melted, said crucible being separate and distinct from said crucible cavity and adapted to empty its molten contents into said crucible cavity; means for causing said crucible cavity to empty its molten contents into said crucible cavity prior to the sealing thereof; means for automatically increasin the initial gas pressure providedin said sealed crucible cavity; and means whereby the gas provided insaid crucible cavity is pre-heated.

11. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for (providing gas under pressure in said seale crucible cavity to force, molten material from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being separate and dis-. tinct from said crucible cavity and adapted to empty its molten contents into said crucible cavity; and means forcausing said crucible to empty its molten contents intosaid crucible cavity prior to the sealing thereof; *mcans for automatically increasing the as pressure provided in said sealed cruci le cavity, from a predetermined initlal pressure to a predetermined final pressure; and means for preheating said gas provided in said sealed crucible-cavity. a

12. In a casting; machine, the combination of a flask containing a mold chamber con nected by a sprueway with a crucible cavity to empty its molten contents into said crucisaidflask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providin a gas under pressure in said sealed cruci le cavit to force molten material from said cruci le cavity into said mold chamber; .a crucible in which the material to be cast is melted, said crucible being separate and distinct from said crucible cavity and adapted ble cavity; means for causing said crucible to empty its molten contents into said crucible cavity prior to the sealing thereof; means a I for automatically increasing the gas pressure provided in said sealed crucible cavity, from a predetermined initial pressure to a predetermined final pressure, within a predetermined period of time; andmeans whereby the gas provided in said crucible cavity is pre-heated. s.

13. In a casting machine, the cambination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said cru-- .ci-ble cavity; means 'for automatically caus-- ing said crucible to empty its molten con- 1 tents into said crucible cavity; and means for melting said material to be cast.

14. In a casting machine, the combination.

of a flask containing a mold chamber con- 'nected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap;,means for providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being separate and distinct from said crucible cavity and adapted its molten contents into said cruto empty cible cavity; and means for causing said crucible to empty its molten contents into said crucible cavity, a blow pipe; aturnable valve for directingthe, flow of gases to said blow pipe, and adapted, onturning, to shut lzo off said gases; and means for automatically 4 turning said valve.

15. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity, means for sealing said crucible cavity with said cap; means for providing-gas under pressure in said sealed crucible cavity to force moltenmaterial from said crucible cavity into said mold chamber;-

a crucible in which the material to be cast is melted, said crucible being separate and dissaid shut off said gases and turn blow pipe out of interference and means for automatically turning said valve.

16. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said .flask; means for melting and delivering metal to be cast to the crucible cavity; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said .cap; means for providing gas under relatively low pressure crucible cavity to force molten material from said crucible cavity into said mold chamber; and automatic means for gradually increasing the initial gas pressure provided in said sealed crucible cavity. a

17. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; means for melting and delivering the metal to be cast to the crucible cavity including a crucible, a blow pipe; a turnable valve for directing flow of gases to said blow pipe adapted to be turned to shut off said gases, means for automatically turning said valve, a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas under relatively low pressure in said sealed crucible cavity to force material from said crucible cavity into said mold chamber; and automatic means for gradually increasing the initial gas pressure provided in said sealed crucible cavity.

18. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; means for melting and delivering the metal to be cast to the crucible cavity including a crucible, a blow pipe, a turnable valve for directing the flow of gases to said blow pipe, said valve carrying said blow pipe and adapted on turning to shutoff said gases and to turn said blow pipe, and means for automatically turning said valve; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap;means for providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavity into said mold chamber; and means for automatically inin said sealed creasing the initial gas pressure provided in said sealed crucible cavity.

19. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity, means for-sealing said crucible cavity with said cap; means for providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being separate and distinct from said crucible cavity and adpted to empty its molten contents into said crucible cavity; and means for causing said crucible to empty its molten contents into said crucible cavity; means for automatically increasing the' initial gas pressure provided in said sealed crucible cavity; andmeans for melting said material-to be cast.

20. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity insaiid. flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means or providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being separate and distinct from said flask and adapted to empty its molten contents into said crucible cavity; means for causing said crucible to empty its molten contents into said crucible cavity; means for automatically increasing the initial gas pressure provided in said sealed crucible cavity; and means for melting said material to be cast.

21. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask; a cap adapted to seal said crucible cavity; means for sealing said crucible cavity with said cap; means for providing gas under pressure in said sealed crucible cavity to force molten material from said crucible cavity into said mold chamber; a crucible in which the material to be cast is melted, said crucible being separate and distinct from said crucible cavity and adapted to empty its molten contents into said crucible cavity; means for causing said crucible to empty its molten contents into said cruible cavity; means for automatically increasing the initial gas pressure provided in said crucible cavity; a blow pipe; a turnabl'e valve for directing the flow of gases to said blow pipe, and adapted, on turning, to shut off said gases; and means for automatically turning said valve.

22. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible arate and distinbt from said crucible cavity and adapted to empty its molten contents into said crucible cavity; means for causing said crucible to empty its molten contents into said crucible cavity; means for automatically' increasing the initial gas pressure provided in said sealed crucible cavity; a blow pipe; a turnable valve for directing the flow of gases to said blow pipe, said valye being adapted for mountingsaid blow pipe thereon, and, on turning, to shutofl said asses and turn said blow pipe out of inter erence; and means for automatically turning said valve. 23. In a casting machine, the combination of a flask containing a mold chamber connected by a sprueway with a crucible cavity in said flask, a cap adapted to seal sa d crucible cavity; means for sealing said crucible cavity with said cap; a gas feed line connected to a source of gas under pressure, and adapted to deliver gas to sa d sealed crucible cavity; a gas regulator in said gas feed line, said regulator being adapted for adjustment to deliver any degree of required pressure, and means for automatically causing said regulator to deliver a gradually increasing degree of pres sure from a predetermined. initial pressure to a predetermined final pressure in a predetermined period of time. a

24. In a casting machine the combination of a flask containing a mold chamber connected by a sprueway-with a crucible cavity in said flask; a cap adaptedto seal said crucible cavity; means for sealing said crucible cavity with said cap; a gas feed line connected with a source of gas under pressure and adapted to deliver gas to said sealed crucible cavity; a gas regulator in said gas feed line, said regulator being adapted for adjustment to deliver any degree ofrequired pressure; a piston, a cylinder in which said piston is mounted, adapted to form a fluid cushion to retard advanced movement of said piston; a spring acting on said piston to advance the latter; connections between said piston and regulator, whereby advanced movement of the said piston will effect adjustment of said regulator from one degree of delivered pressure'to another; means for holding said piston in a retracted position in opposition to said spring; automatic means for releasing said piston from its re- I tracted position, stopping the advanced movement of said piston at a predetermined point, and for gradually venting the fluid cushion opposing the advance movement of ment of said lever will advance said crucible and tilt it over said flask so as to deposit .its molten contents into said flask, and whereby continued movement will retract said crucible before the cap is positioned to seal the flasln 5 26. In a casting machine of the class described, an operating lever, a flask, a cap, operable by said lever for sealing said flask; a crucible pivoted to rock horizontally and tilt vertically; means whereby initial movement of said lever will advance said crucible and tilt it over said flask, so as to deposit its molten contents into said flask, and whereby continued movement will retract said crucible before the cap is positioned to seal the flask; and whereby the whole cycle of movement of said lever, from its initial position to that in which the flask is sealed, and back to the starting position of said lever, will restore said crucible to its initial operating position,

27. In a casting machine of the class described, an operating lever, a .flask, a cap operable by said lever 'for; sealing said flask, a crucible ada ted to empty its molten contents into sai flask,means whereby'initial movement ofsaid lever will cause said crucible to empt its molten contents into said flask,,and w ereby continued movement will retract said crucible out of interference with the positioning of said cap to seal said flask.

28. In a casting machine of the class described, an operating lever, a flask, a cap operable by said lever for sealing said flask, a crucible adapted'to empty its molten contents into said flask, means whereby initial movement of said lever will cause said crucible to empty its molten contents into said flask, and whereby continued movement will I retract said crucible out oi interference with the positioning of-said cap to seal said flask;

and whereby the whole cycle of movement.

of said lever, from its initial position to that.

pressure, followed by a supply of gas of gradually increasing pressure. a

30. In a casting machine'of the class described, an operating lever, a crucible pivoted to swing horizontally; a blow pipe;

":1 turnable valve for directlng thefiow of gases into said blow pipe, and on which the blow pipe is mounted, forming a pivotal support for the latter; means operable by said lever for swinging said crucible and vanced position.

' JOHN A. LENTZ. 

